Endoluminal prostheses may be inserted into a body lumen such as an anatomical vessel or duct for various purposes. Prostheses may maintain or restore patency in a formerly blocked or constricted passageway or they may be used for different procedures. For example, a prosthesis may include one or more stents disposed in or about a graft, and the stents may hold the graft in an open configuration to treat an aneurysm. Additionally, stents coupled to one or both ends of a graft may extend proximally or distally away from the graft to engage a healthy portion of a vessel wall away from a diseased portion of an aneurysm to provide endovascular graft fixation.
Modular stent graft pieces can be deployed in stages to form a combined stent graft assembly. First, a main or central stent graft piece can be deployed. Subsequently, secondary stent graft pieces can be deployed and positioned within the main stent graft piece. This type of staged deployment can require multiple cannulations of the main stent graft lumen.
When a secondary stent graft piece has been deployed and positioned within the main stent graft piece, further movement of a delivery or other device through the stent graft may result in unintended contact between the device and the deployed secondary pieces.
This disclosure describes an apparatus and methods designed to temporarily constrain such devices against a portion of an interior surface of a stent graft so as to avoid contact with secondary stent graft pieces.